Highly ordered iron oxide-mesoporous fullerene nanocomposites for oxygen reduction reaction and supercapacitor applications

In this study, we report a facile synthetic strategy to embed ultra-small iron oxide nanoparticles within the channels of highly ordered mesoporous fullerene (C-60) (Fe-MFC60-T, where T denotes the temperature of the template synthesis). The present work is judicially designed to form the hematite phase of iron oxide (alpha-Fe2O3) nanoparticles (NPs) through the subsequent calcination of Fe-MFC60-T. The Fe-MFC60-T materials were analysed comprehensively for obtaining their physico-chemical properties. Among the materials studied, Fe-MFC60-150 exhibits a unique doughnut-shaped morphology with a high specific surface area ( 598 m(2) g(-1)), crystalline wall structure, and well-ordered porosity. The Fe-MFC60-150 displays an adequate oxygen reduction reaction (ORR) activity with a positive onset potential at 0.85 V (vs RHE) and half wave potential at 0.78 V (vs RHE), low Tafel slope (66 mV per decade), high exchange current density (1.2 x 10(-10) A cm(-2)), and good tolerance towards methanol crossover. We also demonstrate that Fe-MFC60-150 is capable of delivering a specific capacitance of 112.4 F g(-1) at 0.1 A g(-1). The electrochemical performance of Fe-MFC60-150 towards ORR and super capacitor can be ascribed to the synergistic coupling effects between the active sites of alpha-Fe2O3 and MFC60.